Pulverizing or grinding mill.



J. W. WOOD. PULVERIZING 0R GRINDING MILL. APPLICATION FILED AUG. 3,1914. 1, 1 1 6, 1 93. Patented Nov. 3, 1914.

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J. W. WOOD. PULVERIZING 0R GRINDING MILL.

Patented Nov. 3, 1914.

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JACOBWINSLOW WOOD, 0F ALLENTOWN, PENNSYLVANIA.

PULVERIZING 0R GRINDING MILL.

Specification of Letters Patent.

Patented Nov. 3, 1914.

Application filed August 3, 1914. Serial No. 854,814.

of Pennsylvania,.have invented certain new and useful Improvements inPulveri zing or Grinding Mills, of which the following is a description,reference being bad to the accompanying drawing and to the figures of 10reference marked thereon.

My invention relates to pulvenzmg or grinding mills, and particularly tothat class thereof in which the reduction or pulverization of ores andother substances is accomplished by the revolution of one or more rollsWithin and against the inner surfaces of rings or annular dies, and inwhich said rolls are held in contact with said rings or annular dies bycentrifugal force, when the mills are in operation. Perhaps the bestknown types of mills of this character, are the Huntington mills, suchas illustrated in Patents 277,134, of May 8th, 1883, and

325,804, of September 8th, 1885, and the Gritlin mill, illustrated inPatent 409,57 9, of August 20, 1889. While the present invention isapplicable to all mills of these and analogous types, for purposes ofillustration, I have shown my improvements as designed especially foruse in the Griffin mills. In this type of mill, it is the practice toform the roll head of an iron casting chilled on the periphery orcircular surface which comes in contact with the die; and as thechilling of a casting reduces the strength of the latter in proportionto the depth of the chill, there is tendency to break. As usuallyconstructed heretofore, the chilled portion of the roll head ends atabout the upper line of the annular die or ring, and the gray metal onlya fraction of an inch or less above the die and is ordinarily squaredoff. With this construction, the roll head has been liable to spall atthe upper edge in the severe usage to which it is put, and I have foundin practice that this makes the term of service of the roll head veryirregular for when once the spalling begins it continues constantly, sothat in a short time the roll head has the entire upper edge chipped offand thus has to be thrown away and replaced by another.

One of the features of my invention, therefore, relates to the formationof the roll head to overcome this danger, and, in brief,

I have reinforced the casting at its point of greatest weakness and haveredesigned it to redistribute the metal in such a way as. to overcomethe tendency to spall.

Again, in mills of this character, to facilitate the discharge ofmaterial therefrom, a four bladed fan is usually attached to the shaftjust above the roll head, but in designing my novel roll head I cast theblades integral with the same, thus dispensing with a separate castingindependently attached to the shaft.

The invention, therefore, consists in these novel features heretoforereferred to.

The invention is illustrated in the accompanying drawings, in which-F'gure 1 represents a vertical elevation partly in section of a Griffinmill, showing my invention applied-thereto; Fig. 2 is a front View of myimproved roll head; Fig. 3 IS a section thereof; Fig. at is a plan viewof Fig. 2; Fig. 5 is a perspective View of said roll head; Figs. 6 and 7are sectional and plan views, respectively, of a modified form of myinvention; and Figs. 8 and 9 are similar views, respectively, of anotherform.

In these drawings, the mill shown is of the Griffin type, and in generalcomprises the chamber 1, secured to the support 2; the screen frame 3and the encircling trough 4 receiving the material passing through thescreens 5. The discharge spout is shown at 6, the ring or annular dieagainst which the roll is revolved at 7. The roll shaft is shown at 8,and is suspended from a universal joint 9, secured to a drive shaft 10,driving from a pulley 11, or any other suitable gearing. The parts abovereferred to and marked with numerals are of the ordinary constructionand will be understood without further description.

The invention in this case, as above stated, resides primarily in theconstruction of the roll head and one form thereof is shown in Figs. 2,3, 4 and 5. Referring to these figures, the roll head is denoted ingeneral by the numeral 12 and the lower part which bears against the diering by the numeral. 13. The outer tapered face of the roll hearingagainst the die ring projects slightly above the upper face of the dieand then tapers upwardly in the form of a hollow truncated cone adistance of some twelve or fifteen inches above the die. The metal 1above the upper line of the chilled poi-r3011 of the roll head. Formedintegral with the bottom of the roll head are projections 14 forperforming the work of the usual stirrers', common on machines of thischaracter.

. Cast integral with the roll head are the fan blades 15 which are alsoprovided with the strengthening ribs 16. By making the roll head hollowand in the form of a truncated cone great strength is secured withlightness, and, as said above, the casting is reinforced at a point ofgreatest weakness.

Modifications of the structure are shown in Figs. 6 and 7 and 8 and. 9.In Fig. 6 the, roll head is made of less vertical height than in theother form of the invention and instead of being extended upwardly as ahollow truncated cone has the form of a rounded dome 17. So, also, inFigs. 8 and 9 the entire top of the roll head is rounded from a pointjust slightly above the top of the, die, the upper face being roundedand turned inwardly, as shown at 18. In both these modified forms, thefan blades are made integral with the body of the roll head, although itwill be understood that this is not essential.

Copies of this patent may be obtained for tapering inwardly and formedwith a hollowed interior.

2. A roll head having a tapered lower surface to bear on the die ring,and its widest diameter a short distance above the level of the diering, and then tapering inwardly and upwardly, and interiorly hollowedout.

3. A roll head having a tapered lower surface to bear on the die ring,and its widest diameter a short distance above the level of the diering, and in a curved line, and interiorly hollowed out.

4. A roll-head having a surface adapted to bear upon die rings havingits metal.

strengthened upon the level of the die and tapering inwardly and havingfan blades formed integral with the tapered portion.

In testimony whereof, I aflix my signature in the presence of twowitnesses.

JACOB WINSLOW WOOD.

Witnesses:

HENRY GREENAWALD, V. Z. KoHLnR.

five cents each, by addressing the Commissioner of Patents, Washington,D. 6.

